Shotguns having multiple barrels with a firing chamber associated with each barrel are well-known. Examples of shotguns having multiple barrels can be found in U.S. Pat. Nos. 441,389; 1,920,702 and 4,712,323. It is also known to provide a shotgun having two firing chambers and a single barrel. This type of firearm is constructed so that the exit opening from each firing chamber opens into the single barrel. An example of this type of shotgun can be found in U.S. Pat. No. 1,685,673 to Jones. Wright in U.S. Pat. No. 2,727,987 also discloses a gun in which shots from multiple chambers are directed through a single barrel.
In all of the shotguns of the prior art in which multiple firing chambers are connected to a single barrel, all firing chambers are open to the barrel at all times. Consequently, the back pressure exerted by a shell fired from one firing chamber will expand into the other firing chambers. This pressure could damage any shells in the other chamber or chambers.
Prior art shotguns also stow the shells parallel with the barrel. As a result, there is more distortion to the projectile or shot and to the shot string as the shot is propelled forward to ricochet off the outer wall of the forcing chamber and, then again ricochet off the opposite wall of the barrel.